Someone pleaaaase give me the summary since i can't find it.

That song… It sounds like my brother’s unreleased track! Just before his untimely death, Su-in’s beloved older brother recorded an album dedicated to him – a final gift that was soon forgotten in a desk drawer. Years later, Su-in hears one of those tracks on TV, and it’s being claimed by his brother’s former bandmate. Now, Su-in must take the stage, beat the competition, and take back his brother’s songs… all through music

Thanks bae